Organoboron cyclic ethers



Oct. 13, 1964 J. w. AGER, JR., ETAL 3,153,056

ORGANOBORON CYCLIC ETHERS Filed Dec. 1, 1961 FIGURE 1 O BORON 0 CARBON o HYDROGEN ON CARBON (HYDROGEN ATOMS ON BORON OMITTED FOR CLARITY FORMULA I INVENTORS. JOHN w. AGER,JR. BY THEODORE L.HEYING Maw/O49. M

AGENT United States Patent 3,153,056 ORGANOBORON CYCLIC ETHERS John W. Ager, In, Princeton, N.J., and Theodore L.

Heying, North Haven, Conn., assignors to Olin Mathiason Chemical Corporation, a corporation of Virginia Filed Dec. 1, 1961, Ser. No. 157,304 2 Claims. (Ci. 260-3461) wherein R and R are hydrogen or an alkyl group contain- 7 ing from 1 to carbon atoms, can be prepared according to the method described in application Serial No. 801,960, filed March 25, 1959, of John W. Ager, In, et a1- For example, the compound B H [C(CH OH)] can be prepared by hydrolyzing the compound o B uH[C(CHzO( lCH )C(CHzOiilCHQl with a methanolic solution of potassium hydroxide at room temperature for about 4 hours followed by heating at 60 C. for about minutes. On acidification of the reaction mixture the product (B H [C(CH OH)] precipitates and it is then recovered by filtration.

The solid products prepared in accordance with the method of this invention, when incorporated with suitable oxidizers, such as ammonium perchlorate, potassium perchlorate, sodium perchlorate, ammonium nitrate and the like, yield solid propellants suitable for rocket power plants and other jet propelled devices. Such propellants burn with high flame speeds, have high heats of combustion and are of the high specific impulse type. The solid products of this invention, when incorporated with oxidizers, are capable of being formed into a wide variety of grains, tablets, and sheets, all with desirable mechanical and chemical properties. Propellants produced by the method described in this application burn uniformly without disintegration 0n ignition by conventional means, such as a pyrotechnic type igniter, and are mechanically strong enough to stand ordinary handling.

In accordance with this invention, it was discovered that organoboron alcohols of the class can vary widely, provided sufiicient inorganic acid is present to accomplish dehydration, generally being within the range of from about 0.5 to moles of inorganic acid per mole of organoboron alcohol employed and preferably within the range of from about 5 to 20 moles'of inorganic j acid per mole of the organoboron alcohol. The tern perature of the reaction can also be varied widely from about 50 C. to about 300 C. depending upon the particular acid employed and upon the strength of the acid.

Suitable inorganic acid deweight of the oxidizer are used.

Patented Get. 13, 1964 ice Generally, the reaction requires from about 0.1 to 10 hours or more, depending upon the particular reactants and the temperature and pressure employed.

The process of the invention is illustrated in detail by the following example, which is to be considered not limitative.

Example I A total of 5.8 grams of B I-I '[C(CH Ol-ll] and 50 ml. of concentrated sulfuric acid (98 percent by weight); were placed in a sublimation apparatus and heated under vacuum at 110 C. for 6 hours. The sublimate was dissolved in pentane, separated from the insoluble material and dried over magnesium sulfate. Afterfiltering, the solvent was removed and the residue was re-sublimed yielding 4.4' grams of a white solid which was identified by mass spectrometric analysis and by nuclear magnetic resonance spectrum determinations as The boron-containing solid materials produced by practicing the method of this invention can be employed as ingredients of solid propellant compositions in accordance with general procedures which are well understood in the art, inasmuch as the solids produced by practicing the present process are readily oxidized using conventional solid oxidizers, such as ammonium perchlorate, potassium perchlorate, sodium perchlorate, ammonium nitrate and the 7 like. In formulating, a solid propellant composition employing one of the materials produced in accordance with the present invention, generally from 10 to 35 parts by weight of boron-containing material and to parts by In the propellant, the oxidizer and the product ofthe present process are formulated in admixture with each other by finely subdividing each of the materials and thereafter admixing them. The purpose of doing this, as the art is well aware, is to provide proper burning characteristics in the final propellant. In addition to the oxidizer and the oxidizable material, the final propellant can also contain an artificial resin,

generally of theurea-formaldehyde or phenol-formalde- The function of the resin is to give the propeilant mechanical strength and at the same time improve;

hyde type.

its burning characteristics. Thus, in the -manufacture of a; suitable propellant, proper proportions of finely'divided' oxidizer and finely divided boron-containing material can be admixed with a high solids contentsolution of partially condensed urea-formaldehyde or phenol-formaldehyde resin, the proportions being such that the amount of resin is about 5 to 10 percent by weight based upon the weight of oxidizer and boron compound. The ingredients can be thoroughly mixed with simultaneous removal of reference is made to US. Patent 2,622,277 to Bonnell and y to US. Patent 2,646,596 to Thomas.

The compound of-the formula turalformula as structural formula I shown in FIGURE 1 with the exception that the hydrogen atoms indicated by the single and double asterisk are replaced by the radical What is claimed is: 1. An ether of the formula:

wherein R and R are selected from the group consisting 15 of hydrogen and an alkyl group having from 1 to 5 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTS 

1. AN ETHER OF THE FORMULA: 